+ View the NASA Portal + Near-Earth Object (NEO) Program Search JPL JPL Small-Body Database Browser Search: [ help ]   21597 (1998 WA8) Classification: Main-belt Asteroid          SPK-ID: 2021597 [ Ephemeris | Orbit Diagram | Orbital Elements | Physical Parameters | Discovery Circumstances ] [ show orbit diagram ] Orbital Elements at Epoch 2456400.5 (2013-Apr-18.0) TDB Reference: MPO250424 (heliocentric ecliptic J2000)  Element Value Uncertainty (1-sigma)   Units  e 0.0744761 n/a   a 3.0188847 n/a AU q 2.7940499 n/a AU i 11.25729 n/a deg node 60.09366 n/a deg peri 231.79935 n/a deg M 29.89897 n/a deg tp 2456241.3810300 (2012-Nov-09.88103000) n/a JED period 1915.8796836 5.25 n/a n/a d yr n 0.18790324 n/a deg/d Q 3.2437195 n/a AU   Orbit Determination Parameters    # obs. used (total)      748      first obs. used      1996-??-??      last obs. used      2012-09-02      # oppositions      12      planetary ephem.      DE403      condition code      0      fit RMS      0.54      data source      MPC:mpn      producer      MPCLINUX   Additional Information  T_jup = 3.214  [ Ephemeris | Orbit Diagram | Orbital Elements | Physical Parameters | Discovery Circumstances ] Physical Parameter Table Parameter Symbol Value Units Sigma Reference Notes absolute magnitude H 12.4 mag n/a PDS3 (MPO 8801)   21597 (1998 WA8)          Discovered 1998-Nov-18 by Ueda, S., Kaneda, H. at Kushiro (399) Reference: 20010208/Numbers.arc Last Updated: 2004-04-19 [ Ephemeris | Orbit Diagram | Orbital Elements | Physical Parameters | Discovery Circumstances ] 2013-Jun-19 16:59 UT (server date/time)   Site Manager:   Donald K. Yeomans Webmaster:   Alan B. Chamberlin